Trussed girder.



PATENTED SEPT. 1907.

J. KAHN.

TRUSSED GIRDER.

APPLIUATION FILED un. 22. 1907.

3 SHBETS-SHEET 1.

No. 866,140. PATENTED SEPT. l?, 1907. J. KAHN,

TRUSSBD BIEDER.

APPLIUATION FILED APE. 22. 1907l a SEBBT$SHT 2.

Known PATENTED SEPT. QO'.

No. 866,140y

J. KAHN.

TRUSSBD GIRDBR.

Ammonia): rum 93.22. 1901.

3 SHEETS-SHEET 3.

JULIUS KAHN, OF DETROIT, M'GHIGN. i

TRUSSED GIRDER.

Specification of Letters Patent.

Patented Sept. 17, 1907.

Applicotion filed April 22, 1907. Serial No. 369.478.

To all whom it may concern:

Be it known that l, .lomos KAHN, a citizen o the United States, and s. resident oi Detroit, in the county of Wayne and State of Michigan, have invented n new and Improved Trussed Girder, of which the following is o. specification.

While plete girders and I booms are usually cheaper for moderate spons than trussed structures, they are cheaper only because ol the cost of labor necessary to the production of the usual typos ul trusses. Much of the material employed in the common plate girdors and I beams, particularly in the webs, is practically useless, and might be removed, not only with safety, but also with gain in carrying capacity, were the expense o removing the' unnecessary metal not prohibitive. For spans ot' considerable length, much of the strength of plate girders and I beams is required to carry their own weight, and a. much lighter structural member is as desirable, providing,r its carrying power is the same.

My present. invention consistsn s. trussed grder of maximum carrying power for its Weight, being built up of two part trusses, similsr in construction, which, when secured together, form s light truss.

It consists further in the novel details of construction described in the accompanying drawings and particularly set forth in the claims.

In the accompanying drawings, Figure l is a side `view of one form of truss embodying my present invention. Fig. 2 is a view of a. channelbeam properly machined, ready for expanding into a part-truss. Fig. 3 is s cross section on the line 33 of Fig. 2. Fig. 4 is a cross section on the line 4-4 of Fig. l. Figs. 5 and 12 are cross sections oi other forms of channel beams ready to be expanded. Fig. 6 is s View oi another trussed girder embodying my invention. Fig. 7 is a.' view of the beam therefor machined ready lor expanding. Fig. 8 is a cross section on the lino 8-8 of Fig. 6. Fig. 9 is a view of another trussed Vgirder embodying my invention. Fig. 10 is s. View of the channel from which the part trusses of this glrder are formed. Fig. 11 is a cross section on the line ll-ll of Fig. 9. y

Similar reference characters refer `to like parts throughout the several views. l Y

In the construction of trusses for long spans and light loads, l have found that satisfactory girders can be made by using thin sheet steel, and that, owing to the small Weight of the truss,` considerable loading is permissible even on long spans. The sheet metal is lirst rolled in the form of a. channel beam, as shown in Figs. 2 and 3, tho flanges 1 being connected by s web 2. In the middle of the web a ridge or bead 3 is formed. The beam is then slotted transversely at 4, and slots 5 and 6 extend longitudinally from opposite ends of the slots G. This machining of the beam forms upper and lower angles connected by semi-cylindrical momf bers. The ongles 1--2 are then sepsisted, the members 3 bonding at the points 7. The middle portions 8 of the diagonale 3 are flattened and punched, the angles, now the upper and lowor members, are punched, thus completing the parttrusses. Two duplicate part-trus'scs are then secured together by rivets, plates 9 boing secured between their @nter ends, to take up the upward thmst of the supports, and the trussed girder is complete. When loaded, each member acts in the same manner as do the corresponding members oi the Well known Pratt truss.

As the strength of a truss depends virtually v upon the strength of the upper and lower members and the distance between them, the diagonale requiring merely strength enough to resist the crushing stress occasioned 'by the loads, o lightvtruss oi this kind is of ample Y strength for a great variety oi uses, and will carry loads on spans Where an I beam would sag of its own weight.

To stiffen the upper and lower members ol this typo oi truss, it is often desirable to'corrligate the llangesas at ll in Fig. 5, and in certain cases to form a portion 10 of the upper and lower members at'an angle to the web 12 and flanges 14, as shown in Fig. 12. Many other vforms o longitudinal members may be employed in this type of light trussed girder.

In Figs. 6, 7 and 8, another form of truss is illustrated, a form adapted for heavier loads than can be carried by the truss illustrated in Figs. 1, 2, 3, and 4. A channel beam is rolled with lateral flanges 16, web 17, and

's bed or ridge -18 in the conter of the web. Transverse slots 19 and longitudinal slots 20 and 21 are then cut and the holes 22 punched. The beams are formed with ridges or tongues 23 near one edgey .md a corrsspending groove near the other edge. The beams are then expanded, the central portions 18 bending st the points 24. Each beam thus forms s. part-truss, consisting of longitudinal upper and lower members and diagonal members integral therewith. The bend or tongue 23 on one part-truss will be at the top, on the other at the bottom, otherwise the two parts are duplicstes. At the points where the diagonal members 18 cross each other they may be secured together in anydesirztble manner, such :is wrapping with n light rod as shown in the drawing. An expanded plate consisting of longit dinnl upper and lower members 25 andtrsnsvcrse meuibers 2G may be fastened between the two part-trusses in order to stillen the trussed girdr. 'lhe various parts oi this construction sct like the corresponding members o s Howe truss. The plates 27 at theends ol the trussed girder take the thrust of the supports.

loo

los

In Figs. 9, 10 and 11 another form of my improved mms is shown. i e channel beam from which the mm. .trusses 'ined has flanges 30 and web 31. 1 ugonal slotsaiie araif.' the connecting members 33, lln upper sind lower members aro provided with E. mi 34 and are pnnchod for nonnecting rivela. w n expanded and put together, the two pari-trussos i lmr form :i trussnd girdor, and their dingonzils 33 donlfifx wrap .'55 nl lle-.wy wire living Huit-able engaging nimma. llncl pinion 36 muy also bo elnployvdA The ridges or ton-urnas 23 in Fig. 8, and 34 in Fig. ill providvY n'slrong lovk lilwwn tl|r longitudinal mmlwrs ol llnpzirbtrllssos, provonling any lain-:il [novonmni lwtwvvn the-ni nml insuring iin transmission oi' :my lonll Rirnss to lli@v next adjacent diagonzilnA Tiw rivvts ull rombino lo provi-ni longitudinal mov-mont liotwusn thea@ parts.

Having now explained my improvvnwnts, what I olnini as my invention and desire to Serum by Lette-ro Patent ie:-

1. In n truss, thv cmnblnation of two mill-s of angle linrs i'ormlng` ilu' upper und lnwvr longitudinali members ol' tln.` trims. two scrl of diagonal nwnllwrs inclined in opposite directions. muli srl-ins iniegrall willi om' ni' th?. upper und om of flic lower [muli liurs, nimm; io sucurv the dingonnis rogethf-r nl their points of iniiisectlon, and verliuul plnvles soeur-ed llviween ille vnds of the upper and lower longitudinal members uf the truss.

2. In a truss forme-rl of two mirth-msn, enifli comprising upper und lower longitudinal nnrnlm; and diagonali members integral llierrwiill, the dim/finals of lim partl trusses being inclined in opposite diver-rions.

l l r l l l il. A part-truss nomprlslng longitudinal upper und lower member-H In tlm form of nngle liars, and diagonal Lnvmbers integral therlewit'liY 4. A irnss formed of two sin-ct metal part-trusses enrli rouw-rising.; iiunged upper and lower :number-s und selni rylinrlrlcail dlnuonul ruoinllvrs Connor-ling the nume and lnligrn tlwrrvvllli` tint` diagonal nxemlif-r of the purttrnwwsi being invllnvd in nflposinj directions, und tlaitenud ut. tlwlr intersections und tlnerr sl-vnrod iogrvilwr 7. .i lnrlrlinss comprising uppvr nnll Iowfr nninborw, in 1in,- ininl oi" Imm sind nn open work lntlxrinotliuto portion integrali linie-with.

il. A

'i'. A lrnw formal of :i plurality of slim-t :n1-tail purl Einmal. inv of wliiezli rolnprisus longitndinul umu-r :1nd lowvr ins-mimi'. und groovfd wbb nwlnllfrs connrtin.: Illv Anim und intvgrnl tliermvllli.

H. A slr-irlnrnl nnnllwr (ormoni of n plurality of [iuris one of w'nlrn is formed by expanding n rolled suction, and comprises n longitudinal member anni nn oxpumlwl wel: integral tlirrrwilh.

il. A truss formel! of u plurality of puri truss whirl: is fornlvd from n rollpd shff-l or pinto of steel, :unl rounlrinim: n lonuiimlin! niomli-r mi an f-Ipancied wir!) inward* ilwiewlin 1d, A :'.trnrtin-ni mymhor alimen' oi a plurality cani! r-omlfrirng outside llingiiudirwl n'ieznliurs expnndcd iniarnwdlaiw portion integral therewith.

In testimony whereof linie signed this ripploeiion in ille presence cf two subscribing; wltmsnma.

.l'iLl US HAHN.

s, one of 

